Just a quick post to share how I handle XP in my 'Lamentations of the Flame Princess' campaign.
I use the XP for monsters and treasure as given. At first I thought of using the XP for monsters from 'Castles & Crusades' but ended up realizing they're actually pretty close on average, and truth be told LotFP's is less hassle.
However, I have adopted some XP methods from 'Castles & Crusades' into the game. Not the one that gives XP to a player for owning magic objects though, that one I think is a bit weird. A 'traditional' magic object already makes you more powerful, why exactly should it also give you XP? Anyway. Maybe I'd give extra XP to players who keep a cursed object though, as they learn new tricks to compensate for the problem it causes them. Same goes for a player who gets maimed. (for that, I'd use Story XP, which I'll mention in a moment.)
I have decided to use their XP for role-playing too. It felt like the least I could do after all of the player's characters had their teeth pulled out last session and they had to talk/act as such.
I've also decided I'm going to use C&C's XP for Story. Now, I won't award 'Story XP' for things like 'Succeeded in the Goal of Killing the Troll under the Bridge' or anything like that. The XP from killing the monster already covers that. (Although I could see it used for defeating a whole organization where a lot of planning was needed.) Instead, some characters or Hexes in my map contain secrets. If the characters discover such secrets, they get a bonus XP from having learned more about the world they inhabit. (A King's secret will be worth a lot more XP than a local farmer's!) I also recently read on another blog (Which I'll try to find again and link here at a later date/edit!) the idea of XP for traveling. I think it's a good idea to give certain difficult locations XP for finding them, again using the Story XP as a guideline. Not for 'normal' things like a dungeon and such, but maybe things like discovering a new dimension or traveling to another continent and dealing with a whole new culture for a prolonged time.
Finally, since neither LotFP nor C&C give XP for traps, I'll use once again the Story XP rewards for the traps. Seems like an easy way to acknowledge that dealing with traps should also make characters more experienced, not just smacking monsters and other enemies down and snatching their loot.